Electron discharge device



Aug. 8, 1950 J. STlVlN ELECTRON DISCHARGE DEVICE FiI ed Aug. 25, 1948 vy 2 z w a Q g g 1 a z vfi 5 k 5 MW 0 Z 5 IYWIIIA Q j F Patented Aug. 8 1950 ELECTRON DISCHARGE DEVICE J ii-i Stivin, Rychnov, near J ablonec nadNisou, Czechoslovakia Application August 25, 1948, Serial No. 46,122 InCzechoslovakia August 26, 1947 The present invention relates toimprovements in electron discharge device and is an improvement of theinvention according to U. S. Patent 'No. 2,466,565 issued April 5, 1949,which discloses an electron discharge device with an outer anode,wherein the cathode and grid leads are placed in leading-in members,mounted on the cover of the. discharge or anode vessel and made at leastpartially of glass tubes, insulating the leads from the anode whichforms the discharge vessel, said leading-in members being enclosedwithin a container provided above the discharge vessel itself and filledwith an insulating liquid such as oil.

The present invention relates to improvements in, or modification of,the above electron discharge device. According to one feature of thepresent invention the lower metal portion of the leading-in members,provided on the cover of the anode vessel, are made integral with thecover of the same, preferably by a pressing operation; the connection ofthe upper edges of the said metal portion with the lower ends of theglass portions of the leading-in members may be carried out in the sameway as the connection of the upper ends of the glass portions with theupper metal caps of the said leading-in members, i. e. by means of highfrequency sealing or fusing. In this way the necessity of providing asealing of the contact surfaces on the lower ends of the leading-inmembers and on the cover of the anode vessel is dispensed with and theentire sealing of the electron discharge device is limited to thesealing between the cover of the anode vessel and the upper edge of thevessel. Preferably a steel sealing ring is employed for carrying out thesealing operation. In this way an easy dismantling of the electrondischarge device is possible.

According to a further feature of the invention recesses in the form ofa shallow spherical sector are provided at the lower side in the bottomsof the upper caps of the leading-in members, arranged on the cover ofthe anode vessel, said recesses serving to receive annular washerssecured at the ends of rod-like carriers of the filament and grid, theupper side of the Washers having a corresponding spherical formation.The upper ends of the carriers are secured to the bottoms of the metalcaps by means of rings or annular gibs which are slid on the rod-likecarriers and fastened by means of a number of circumferentially spacedscrews, screwed into threaded holes provided in the bottom of the metalcaps around the said recesses. In this way a perfect and rigidconnection is achieved, the spherical 3 Claims. (01. 250-275) formationof the contacting surfaces assuring automatic centering of the variousparts. The ends of the molybdenum carriers pass preferably through thewashers provided thereon and are ground together with the upper side ofthe washers to the spherical shape so that a direct contact between theend of the molybdenum carriers with the bottom of the metal caps of theleadingin members is achieved. According to a further feature of theinvention the metal cup mounted at the end of the grid between the endof filament and bottom of the anode vessel, is provided withperforations so as to serve as a portion of the grid, increasing thusthe operative surface of the anode by the area of its bottom.

By the said provisions an extraordinary simplification of manufactureand assembly of the electron discharge device is achieved. The containerof the discharge device consists substantially of the anode vessel andits cover, provided with leading-in members, the metallic lower portionsof which are made integral with the cover. The connection of the saidmetal portions with the glass portions of the leading-in members, aswell as the connection of the glass portions with the metal caps ispreferably carried out by a high frequency sealing or fusing operation.The container of the discharge device consists, therefore, of an anodevessel and cover with leading-in members. The inner system of thedischarge device consists of a grid, carried by molybdenum carriers, andfilament, carried by molybdenum carriers as well. In consequence of theabove described arrangement the grid with its carriers and the filamentwith its carriers may be fully assembled and then simply fastened byscrewing the same to the upper portion of the discharge devicecontainer, so that the two electrodes are carried by the cover of thevessel. The cover, together with the grid and filament is thenin sertedinto the anode vessel, while the contact portions between the anodevessel and the cover are suitably sealed.

The described simple assembly operation makes it possible to easilyremove impurities from the inner surface of the glass portions of theleadingin members, which impurities are deposited thereon during theheating of the electron discharge device carried out for the purpose ofexpelling the occluded gases. The discharge device may be assembled andits filament and grid subjected to heat treatment in a known mannerunder a simultaneous evacuation of gases. During this operation theevaporated metal particles of the "like carriers or leads.

electrodes condense on the cooler portions, 1. e. on the anode, coverand inner surface of the glass portions of the leading-in members. Suchparticles could be objectionable in the leading-in members, as theywould reduce the insulating resistance between the electrodes. Owing tothe possibility of an easy dismantling of the discharge device it is,therefore, possible to remove the cover after the degassing operation ofthe filament and grid has been completed and to clean the soiled surfaceof the glass leading-in members with a suitable chemical solution. Inthe final assembly of the discharge device a new clean anode is used asthe proper anode, whereas the anode which has been soiled in thedegassing operation is used for degassing of other discharge devices, sothat the so called soiled anode serves only for the manufacture ofdischarge devices.

The individual branches of the filament are secured by their upper endsto two concentric rings, made integrally with the molybdenum rod- Theupper ends of the individual branches of the filament are secured tothe'rings by passing the ends of the wires of an electron dischargedevice carried out according to the invention will now be described withreference to the accompanying drawing wherein:-

Fig. 1 represents in longitudinal section the j.

electron discharge device alone without the outer cover or coolingjacket,

Fig; 2 shows in a cross-sectional view on a through small holes drilledin the rings, and the 4 glass-tubes 8 to all lower portions I0, whichare integral with the cover 3, because there would not be space enoughfor instance for sealing by means of a gas flame.

The cover 3 is further provided with an evacuating tube which mayconsist of a copper tube 88 secured to the cover. The end of the tube 88carries a glass tube 8! sealed thereon, the glass tube 8| being adaptedto be closed or sealed in the usual way after the discharge device hasbeen evacuated.

' The upper bottoms of the metal caps 6 consist, as apparent inparticular from Fig. 2, of relatively thick copper discs 5| provided attheir top with extensions 52 carrying a screw thread serving for the,attachment of the current supply conductors. The lower sides of thebottom 5| are provided centrally with shallow recesses 53 having theshape of a. shallow spherical sector. The upper ends of the grid andfilament carriers 54', consisting of molybdenum rods, areprovided withannular-copper washers 55; the upper ends of the molybdenum carriers arerigidlysecured in the central bore of the washers. The-upper side of thewashers 55 is ground together-"with the molybdenum-carrier- 54 to theshape'of a spherical surface'coinciding with the spherical recess 53.The rod-like carriers 54 are-secured to thebottoms 51 of the cup 6 bymeans of annular gibs or rings 55 slid over the carrier 54 andprovidede. g.- with three circumferentiall-y spaced holes serving forthe reception of screws 51 which are screwed into threaded holes 58 inthe bottom 5! of the metal cap 6; I r

In assembling the discharge device the cover I 3 with the leading-inmembers is placed inreflarger scale the manner of securing the ends of pp the rod-like carriers to the bottoms of the upper metal caps of theleading-in members,

Fig. 3 shows diagrammatically the method of securing the upper ends ofthe individual filament branches to the carrier of the filament and iFig. 4 is a modification of the arrangement on Fig. 3.

Figure 5 is a top view of the device shown in Fig.- 1.

As shown in Fig. 1 the electron discharge device consists of an anode oranode-vessel I, closed on top by a cover 3 provided with leading-inmembers. Each such leading-in member consists of a lower metal portion10, central glass portion 8 and upper closing metal cap 6; Thisarrangement is similar to the arrangement according to U. S. Patent No.2,466,565, issued April 5, 1949.

According to the present invention the metallic portions 10 of theleading-in members are made integral with the cover 3. The cover,together with the lower portions of the leading-in members is preferablypressed from a copper sheet disc which renders its manufacture extremelysimple. The glass portions 8 may be made of glass tubes, if requiredwith walls of considerable thickness,

said tubes being closed on top by metal caps 6 sealed to the glasstubes. The sealing of the lower ends of the glass tubes 8 to the upperedges oftthe metal portions l0 may be carried out by ahigh frequencyheating process. It is only this process which. makes possible .thesealing of the versed position on a suitable support, e. g. table,whereupon the filament and then the gridare secured thereto byintroducing their carriers 54 into the corresponding leading-in members,while in their reversed position. By means of a long screwdriver thescrews 51, inserted beforehand are screwed in, so as toclamp the washer55-at the end-of-the carrier 54between the bottom 5| and ring 56. Thisarrangement allows compensation of deviations, ifany, in addition to-anextremely simple way of fastening, while owing to the-arrangementof thespherically shaped contactsurface between the bottom 51 and washer 55the individual carriers areautomatically centered. The upper end of thecarrier 54 passing through the washer 55, a directcontact between thecarrier 54- andbottom 51 is achieved. The filament conductors, to whichthe individual U-shaped portions of the filament, extendinginto theanode vessel l, are secured; have intheir lower portion the shape of tworings 61 and- 62 mounted one inside the other. One end of" each filamentwire 63is connected with the ring 6| and: the other with the ring 62 sothat all filament wires 63-are connectedinparallel. The upper ends ofthe wires63 are secured to rings- 6l and 62 by being passed throughholes drilled'in the said rings. The upper ends of the wires 63,protruding above therings BI and 82 are swaged into small balls 64-, tosecure the wires 63 tothe rings 5| and 62. The upper portions of thewires, con nected with the inner ring 62 are bent inwardly at an angleand-their end portions are bent back again into vertical directionaccording to Fig.3, or the holes inthe inner ring 62 may be drilled atan angle so as to receive the wires according to; Fig. 4.

The fastening .ofthe filament wire 63 to" the carrying rings it and 62is. extremelysimple whlle permitting easy replacement of the damagedfilament wire, as the required balls 64 may be simply ground away and anew wire 63 secured in a similar way.

The grid is made of a wire 30, wound in a helix or in the shape of wirerings around axially extending carrying wires 3|. The carrying wires aresecured on top to a ring H and at their lower end to an annular rim 12of a cup 13. The ring I! is secured to one or two grid-carriersconsisting of molybdenum rods. The lower cup 13 has usually a fullbottom and serves to close the lower end of the grid. According to thepresent invention the cup is perforated, as shown in the drawing, or itsbottom is made of a wire mesh, preferably of wires of the same thicknessand arranged at the same distance from each other as in the otherportions of the grid, while the distance between the cup and the bottomof the anode and between the cup and the lower portion of the filamentis equal to the distance between the proper grid 30 and the annularportion of the anode and the axial portions of the filament wires 63.The cup 13 forms therefore a portion of the grid so that the operativesurfaces of the grid and anode are thus increased by the said cup andthe bottom area of the anode.

In assembling the electron discharge device according to the presentinvention the cover 3 with the leading-in members with filament and gridcarriers, secured. in the caps 6, which have already been assembled, isinserted into an auxiliary anode which is similar to a normal anode. Thesealing operation between the rim of such anode and the rim of the cover3 may be preferably carried out by means of a sealing ring 82.

After the discharge device has been assembled and evacuated, it isconnected into suitable current circuits which bring the electrodes to asuitable temperature while further evacuation takes place. In this waythe degassing of all components of the discharge device is achieved.During this process metallic articles are, however, released, soilingvarious portions of the discharge device including the anode and theupper portion of the container of the discharge device. According to theinvention the electron discharge device is dismantled after thedegassing operation, its glass portions as well as carriers etc. arechemically cleaned by a suitable chemical substance and the whole systemis then inserted into a new clean anode I, whereupon the electrondischarge device is finally closed and evacuated, during which operationthe anode is degassed.

The soiling of the auxiliary anode is not objectionable and such anodemay be used for the degassing of further discharge devices. If requiredit may also be cleaned from time to time.

While I have disclosed the principles of my invention in connection withone embodiment, it will be understood that this embodiment is given byway of example only and not as limiting the scope of the invention asset forth in the appended claims.

I claim:

1. An electron discharge device comprising in combination, a closedanode vessel having a top wall; inlet openings in said top wall of saidanode vessel; tubular leading-in members extending upwardly from saidanode vessel and each including a metal lower portion being integralwith said top wall of said anode vessel and surrounding one of saidinlet openings, an intermediate glass portion having its lower endconnected to the upper edge of said metal lower portion and a metal caphaving its lower edge connected with the upper end of said intermediateglass portion, each of said caps having at its lower side a recessshaped as a shallow spherical sector; cathode and grid leads passingthrough said tubular leadingin members and through said inlet openingsinto said anode vessel; annular washers electrically connected,respectively, to said cathode and grid leads, the upper side of each ofsaid washers having a convex spherical surface, corresponding to saidrecess in the lower side of said metal upper caps, each of said washersbeing seated in one of said recesses; annular gibs, each of said gibsbeing slid on one of said cathode and grid leads; a plurality ofcircumferentially spaced screws, screwed into threaded holes of each ofsaid metal caps around said recess and connecting, respectively, saidgibs to said metal caps; and an upper vessel surrounding said tubularleading-in members and extending upwardly from said anode vessel, thebottom edge of said upper vessel being filled at least partly by aninsulating and heat conducting liquid.

2. An electron discharge device as claimed in claim 1, each of the upperends of said cathode and grid leads passing through one of said washersin order to obtain direct contact of said lead with the bottom of one ofsaid metal caps.

3. An electron discharge device comprising in combination, a closedanode vessel having a top wall; inlet openings in said top wall of saidanode vessel; tubular leading-in members extending upwardly from saidanode vessel and each including a metal lower portion being integralwith said top wall of said anode vessel and surrounding one of saidinlet openings, an intermediate glass portion having its lower endconnected to the upper edge of said metal lower portion and a metalupper cap having a lower ed e connected with the upper end of saidintermediate glass portion; cathode and grid leads passing through saidtubular leading-in members and through said inlet openings into saidanode vessel electrically connected with said metal upper caps of saidtubular leading-in members; two metal rings of diiierent diameters beingsecured, respectively, to the lower end of one of said cathode leads;one of said rings being arranged inside the other; a cathode including aplurality of U-shaped wires; one of the upper ends of each of said wiresbeing secured to one of said rings and the other of the upper ends ofeach of said wires being secured to the other of said rings, said ringshaving holes traversed by the upper ends of said wires, the ends of saidwires protruding above said rings being swaged into small ball-shapedmembers; and an upper vessel surrounding said tubular leading-in membersand extending upwardly from said anode vessel; the bottom edge of saidupper vessel being sealed to the anode vessel and said upper vesselbeing filled at least partly by an insulating and heat conductingliquid.

Jrni STIVIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,079,137 Varian May 4, 19372,317,442 Chevigny Apr. 27, 1943 2,408,239 Spencer Sept. 24, 19462,431,114 Scullin Nov. 18, 1947 2,452,401 stivin Oct. 26, 1948 2, ,565.Stivin Apr. 5, 1949

